WEST PALM BEACH — Proper attire required, the sign outside the downtown nightclub reads.

No attire is what police say they found there this month.

Undercover agents from the West Palm Beach Police Department visited Club Ohm and saw what they thought were live sex acts broadcast on a screen in the bar, according to a court record filed Tuesday.

Club Ohm is catty-corner from the Palm Beach County Courthouse, between city hall and the police department. Police believe the club has since stopped allowing the filming.

Mayor Lois Frankel said she had no idea what had been found there.

“Oh my goodness, oh my goodness,” she said Tuesday upon hearing of the film shoot. “No, I think I would have remembered this.”

According to the record, undercover agents visited Ohm Bar after someone told them people were shooting live porn in the “VIP” room every Wednesday night. People could pay to watch or participate, the informant said.

So undercover agents visited June 9. Filmmakers even asked the agents to play a clothed role, chatting with the young actress before her partner arrived and whisked her away to the VIP room, where a camera was set up, according to a police report.

Club owner Ronald Vantassell, 28, said it was all a “smoke and mirrors” ruse to attract customers. No one was having sex in the VIP room, and there was no film in the cameras, he said.

A spokeswoman for the West Palm Beach Police Department said that after their initial visit, officers got a search warrant to gather evidence. But when they returned on the scheduled filming night a week later, June 16, there was no filming going on and there hasn’t been any since, spokeswoman Dena Kimberlin said.

In the court record, police allege violation of obscenity laws, including distributing it near children. There is also a Catholic school nearby. No arrests were ever made, though.

Police have since monitored the club and there’s been no further “adult entertainment” there, they wrote in a report.

A company called Triton Productions organized the shoot, advertising it on adult sites on the Internet as “Sex in the Nightclub” scenes. The last performance at Ohm was supposed to be tonight.

Frankel, after making a call or two about it Tuesday evening, figured out the city Planning & Zoning department had been notified by police and sent a cease-and-desist order to the bar.

Frankel said she knew of no organized effort to bring adult entertainment downtown.

Ohm is expected to be open tonight. There will be a DJ and bartender there. That’s it, Vantassell said.

Proper attire required.